This week’s pearls is a series on “Name that Poisonous Beast!”. So, let’s start.
Name this poisonous beast:
A)
And its 8-legged colleague:
B)
- A) Brown Recluse spider (Loxosceles): cytotoxic, hemolytic venom
- Initially unnoticed bite
- Within hours: painful, local erythema
- 6 hours: hemorrhagic blister, blanching
- 2-4 days: ecchymotic, necrotic, local tissue loss
- Less frequent – systemic findings: malaise, nausea/vomiting, fever, myalgias
- Rare complications: hemolysis, coagulopathy, renal failure, death
- Treatment: dapsone (questionable efficacy, only in first 48 hours, ensure no G6PD deficiency), antihistamines, steroids, topical nitroglycerin, hyperbaric oxygen (wound care)
- Antivenom not available in US; only in South America (more dangerous species), though definite benefit not established
- B) Black widow spider (Latrodectus): excitatory neurotoxin venom (via exocytosis of NTs)
- Initially minimal pain
- Target lesion (blanched circular patch w/surrounding red perimeter and central punctum)
- 1 hour – systemic symptoms, including:
- Muscle cramping, nausea/vomiting, headache, anxiety
- Hypertension, tachycardia, tachypnea, diaphoresis
- Abdominal rigidity
- Weakness, fasciculations, paraesthesias, ptosis, lacrodectus facies [facial spasm, eyelid edema, lacrimation]
- Rare: pulmonary edema, CV collapse, cardiomyopathy, ileus, priapism, hematuria, Horner syndrome, compartment syndrome, rhabdomyolysis, TEN, death
- Treatment: local wound care, analgesia, muscle relaxants (benzodiazepines, methocarbamol, unclear efficacy), antiemetics
- Antivenom only for severe cases (poses high risk for allergy, serum sickness)
- Do not give IV calcium for muscle pain/spasms
